Ventilation device for a motor vehicle heat exchange module with air guides for guiding the air flow passing through the air manifolds

ABSTRACT

A ventilation device (2) for generating an air flow through a motor vehicle heat exchanger (1) is disclosed. The ventilation device (2) includes a plurality of ducts (8), at least one air manifold (12) including at least one air flow inlet (131; 132) and ports, each duct (8) opening at one of the ends thereof into a port (14) separate from the air manifold (12), where the air manifold (12; 100; 200; 300; 400; 500) is provided with air guides (104, 402) configured to guide the air flow passing through the air manifold (12; 100; 200; 300; 400; 500).

The present invention concerns a motor vehicle heat exchanger module.

A motor vehicle heat exchanger generally comprises tubes in which aheat-transfer fluid is intended to circulate, and heat-exchange elementsconnected to those tubes, often designated by the term “fins” or“spacer”.

The fins enable the area of exchange between the tubes and thesurrounding air to be increased. However, in order to increase theexchange of heat between the heat-transfer fluid and the surroundingair, a ventilation device is frequently used as well to generate a flowof air directed toward the tubes and the fins.

A ventilation device of the above kind most often comprises a helicalfan, which has numerous disadvantages.

Firstly, the assembly formed by the helical fan and its drive systemoccupies a large volume.

Moreover, the distribution of the air blown by the fan, often placed atthe center of the row of heat-exchange tubes, is not homogeneous overall of the area of the heat exchanger. In particular, certain regions ofthe heat exchanger, such as the ends of the heat-exchange tubes and thecorners of the heat exchanger, are not reached much if at all by theflow of air blown by the fan.

Finally, if it proves unnecessary to start up the ventilation device, inparticular when the flow of surrounding air created by the movement ofthe motor vehicle is sufficient to cool the heat-transfer fluid, theblades of the fan mask part of the heat exchanger. Part of the heatexchanger is therefore not or not much impacted by the flow ofsurrounding air in this case, which limits the exchange of heat betweenthe heat exchanger and the flow of surrounding air.

Moreover, there is known from the German patent DE 10 2011 120 865 amotor vehicle having a ventilation device and a heat exchanger, theventilation device being adapted to generate a flow of air through theheat exchanger. The ventilation device is adapted to create a secondaryflow of air from a primary flow of air emitted from one or more annularelements, the secondary flow of air being much stronger than the primaryflow of air. According to the above patent, the ventilation device formspart of a cooling grille disposed on the front panel of the motorvehicle.

In this kind of motor vehicle each annular element is fed with a flow ofprimary air by a single fan disposed outside the annular element, via aduct opening in a localized manner into the annular element.Consequently, the flow of ejected air emitted by the annular element isnot homogeneous over the contour of the annular element. To thecontrary, the flow of emitted air is greater closer to the fan. Therefollows from this the creation of a secondary flow of air through theheat exchanger that is also not homogeneous.

Finally, there is known from the application DE 10 2015 205 415 aventilation device intended to generate a flow of air through a heatexchanger comprising a hollow frame and at least one hollow crossmemberdividing the surface delimited by the frame into cells. The frame andthe crossmember(s) are in fluid communication with an air flow feedturbomachine. The turbomachine is disposed outside the frame. The frameand where applicable the crossmember(s) are moreover provided with anopening for ejection of the flow of air through them.

Once again, the ventilation device does not enable generation of ahomogeneous flow of air through the heat exchanger. To the contrary, theflow of air emitted by the device is all the greater if it is ejectedfrom the ventilation device in the vicinity of the turbomachine.

The invention aims to propose an improved ventilation device free of atleast some of the disadvantages referred to above.

To this end, the invention proposes a ventilation device intended togenerate a flow of air through a motor vehicle heat exchanger, theventilation device comprising:

-   -   a plurality of ducts,    -   at least one air manifold including at least one air flow inlet        and ports, each duct opening at one of the ends thereof into a        port separate from the air manifold, each duct having at least        one opening for the passage of a flow of air through said duct,        the opening being separate from the ends of the corresponding        duct, the opening being situated outside the at least one air        manifold,

in which the at least one air manifold is provided with air guidesconfigured to guide the flow of air passing through the air manifold.

The air guides for the flow of air advantageously enable morehomogeneous feeding of the various ducts of the ventilation device,thereby enabling a more homogeneous effect of the ventilation deviceover all of its surface. The air guides also make it possible to limitthe head losses of the flow of air in the ventilation device, whichmakes it possible to improve the efficiency of that ventilation device.

The ventilation device preferably has one or more of the followingfeatures, separately or in combination:

-   -   the air guides comprise means for distributing the flow of air        entering the manifold via said at least one air flow inlet        toward the ports,    -   the distribution means include partitions inside the at least        one air manifold,    -   for each air manifold:        -   the number of partitions is zero if the ratio of the area of            the inlet of the manifold to the total area of the ports is            greater than 1.5, and/or        -   the number of partitions is equal to three if the ratio of            the area of the inlet of the manifold to the total area of            the ports is between 1 and 1.5 inclusive; and/or        -   the number of partitions is equal to 5 or more if the ratio            of the area of the inlet of the manifold to the total area            of the ports is less than 1,    -   the or each partition is rectilinear, partly rectilinear or        curved,    -   at least one partition extends, in the vicinity of the air flow        inlet, in a first direction, said at least one partition        extends, in the vicinity of the ports, in a second direction,        and the first and second directions are substantially        perpendicular,    -   the air guides comprise, in the vicinity of the ports,        deflectors adapted to deviate the flow of air to the vicinity of        the ports, so that the flow of air passing through the ports is        directly substantially in a direction normal to the section of        the ports,    -   each deflector is rectilinear, partly rectilinear or curved,    -   the deflectors are in one piece with the at least one air        manifold,    -   at least one partition and/or at least one deflector include(s)        an electrically conductive material,    -   each duct has, over at least one portion, a geometrical section        comprising:        -   a leading edge;        -   a trailing edge opposite the leading edge;        -   first and second profiles, each extending between the            leading edge and the trailing edge,

said at least one opening of the duct being on the first profile, saidat least one opening being configured so that the ejected flow of airflows along at least a portion of the first profile,

-   -   each duct has, over at least one portion, a geometrical section        comprising:        -   a leading edge;        -   a trailing edge opposite the leading edge;        -   first and second profiles each extending between the leading            edge and the trailing edge,

at least one opening of the duct being configured on the first profileso that the ejected flow of air flows along at least a portion of thefirst profile and at least one opening of the duct being configured onthe second profile so that the ejected flow of air flows along at leasta portion of the second profile,

-   -   the ducts are substantially rectilinear tubes, aligned in such a        manner as to form a row of tubes;    -   the opening is a slot in an external wall of the duct, the slot        extending in a lengthwise direction of the duct, preferably over        a least 90% of the duct length and/or the height of said at        least one opening is greater than or equal to 0 5 mm, preferably        greater than or equal to 0 7 mm, and/or less than or equal to 2        mm, preferably less than or equal to 1.5 mm;    -   each duct has, over at least one portion, a geometrical section        comprising:    -   a leading edge;    -   a trailing edge opposite the leading edge;    -   first and second profiles, each extending between the leading        edge and the trailing edge,

said at least one opening of the duct being on the first profile, saidat least one opening being configured so that the ejected flow of airflows along at least a portion of the first profile,

-   -   said at least one opening of the first profile being delimited        by an outer lip and an inner lip, one end of the inner lip being        extended, in the direction of the second profile, beyond a plane        normal to the free end of the outer lip, the passage section        then being defined as the portion of the section of the tube        disposed between said end of the inner lip and the trailing        edge, on the one hand, and between the first and second        profiles, on the other hand,    -   the maximum distance between the first and second profiles, in a        lengthwise direction of the ducts, is downstream of said at        least one opening, in the direction of flow of said flow of air        ejected via said at least one opening, the maximum distance        preferably being greater than or equal to 5 mm, preferably        greater than or equal to 10 mm, and/or less than or equal to 20        mm, preferably less than or equal to 15 mm, the maximum distance        being even more preferably equal to 11.5 mm,    -   the first profile includes a convex portion the summit of which        defines the point of the first profile corresponding to the        maximum distance, the convex portion being disposed downstream        of the opening in the direction of flow of the flow of air        ejected via said at least one opening,    -   the first profile includes a substantially rectilinear first        portion, preferably downstream of the convex portion in the        direction of flow of said flow of air ejected via the at least        one opening, in which the second profile includes a        substantially rectilinear portion, preferably extending over a        majority of the length of the second profile, the first        rectilinear portion of the first profile and the rectilinear        portion of the second profile forming a non-flat angle, the        angle preferably being greater than or equal to 5° and/or less        than or equal to 20°, preferably substantially equal to 10°;    -   the rectilinear first portion extends over a length of the first        profile corresponding to a length, measured in a direction        perpendicular to the direction of alignment of the ducts and to        a longitudinal direction of the ducts, greater than or equal to        30 mm, preferably greater than or equal to 40 mm, and/or less        than or equal to 50 mm,    -   the first profile includes a rectilinear second portion,        downstream of the rectilinear first portion in the direction of        flow of the flow of air ejected via the at least one opening,        the rectilinear second portion extending substantially parallel        to the rectilinear portion of the second profile, the first        profile preferably including a rectilinear third portion,        downstream of the rectilinear second portion of the first        profile, the rectilinear third portion forming a non-flat angle        with the rectilinear portion of the second profile, the        rectilinear third portion extending substantially as far as a        rounded edge connecting the rectilinear third portion of the        first profile and the rectilinear portion of the second profile,        the rounded edge defining the trailing edge of the profile of        the duct,    -   the distance between the rectilinear second portion of the first        profile and the rectilinear portion of the second profile is        greater than or equal to 2 mm and/or less than or equal to 10        mm, preferably less than or equal to 5 mm;    -   said geometrical section of the duct has a length, measured in a        direction perpendicular to the direction of alignment of the        ducts and to a principal direction in which the ducts extend,        greater than or equal to 50 mm and/or less than or equal to 70        mm, preferably substantially equal to 60 mm,    -   the ventilation device comprises at least one first duct and at        least one second duct, the first profile of the first duct        facing the first profile of the second duct,    -   the ventilation device further comprises a third duct, such that        the second profile of the second duct faces the second profile        of the third duct, the distance between the center of the        geometrical section of the second duct and the center of the        geometrical section of the third duct preferably being less than        the distance between the center of the geometrical section of        the first duct and the center of the geometrical section of the        second duct, and    -   each duct is symmetrical with respect to the plane containing        the leading edge and the trailing edge, so that each duct        includes two symmetrical openings, one on the first profile and        on the second profile.

The deflectors of the flow of air advantageously enable guidance of theflow of air in the ducts of the ventilation device limiting head lossesand guiding it in a preferred direction.

The invention also concerns a motor vehicle heat-exchange modulecomprising:

-   -   a heat exchanger, the heat exchanger including a plurality of        tubes, termed heat-exchange tubes, in which a fluid is intended        to circulate, and    -   a ventilation device as described above, adapted to generate a        flow of air toward the heat-exchange tubes.

The invention will be better understood on reading the followingdescription given by way of example only and with reference to thedrawings, in which:

FIG. 1 is a perspective view of one example of a heat-exchange modulewith a heat exchanger provided with part of a ventilation device;

FIG. 2 is a diagrammatic view in section on the plane II-II of anaerodynamic tube of the ventilation device from FIG. 1;

FIGS. 3 to 7 show diagrammatically in section examples of an air inletmanifold that can be employed in the ventilation device from FIG. 1; and

FIGS. 8 to 11 are views analogous to that of FIG. 2 of variant tubes ofthe ventilation device from FIG. 1.

In the various figures, identical or similar elements, having anidentical or analogous function, bear the same references. Thedescription of their structure and of their function is therefore notsystematically repeated.

There has been represented in FIG. 1 an example of a heat-exchangemodule 10 with a heat exchanger 1 intended to equip a motor vehicle,equipped with a ventilation device 2 in accordance with a firstembodiment.

The heat exchanger 1 comprises heat-exchange pipes 4 in which a fluid isintended to circulate, here water or cooling liquid. The heat-exchangepipes 4 are substantially rectilinear here and extend in a longitudinaldirection. The heat-exchange pipes therefore form heat-exchange tubes 4.The heat-exchange tubes 4 are parallel to one another and aligned insuch a manner as to form a row. The heat-exchange tubes 4 are allsubstantially the same length.

The heat-exchange pipes 4 each extend between a fluid inlet manifold 5and a fluid evacuation manifold 6, common to all the heat-exchange pipes4. The ports of the fluid inlet manifold 5, into which the heat-exchangepipes 4 open, are preferably all contained in the same first plane.Likewise, the ports of the fluid evacuation manifold 6, into which theheat-exchange pipes 4 open, are all contained in the same second plane,preferably parallel to said first plane.

More particularly, and conventionally in motor vehicle heat exchangers,each heat-exchange pipe 4 has a substantially oblong section, and isdelimited by first and second plane walls that are connected toheat-exchange fins. For reasons of clarity, the fins are not representedin FIG. 1.

The heat-exchange module 10 is equipped with a ventilation device 2comprising a plurality of ventilation pipes 8. The ventilation pipes 8,in the same manner as the heat-exchange pipes 4, are substantiallyrectilinear, in such a manner as to form ventilation tubes 8. Theventilation tubes 8 are moreover parallel to one another and aligned insuch a manner as to form a row of ventilation tubes 8. The ventilationtubes 8 are also of the same length. The length of the ventilation tubes8 is for example substantially equal to the length of the heat-exchangetubes 4.

The ventilation device 2 is intended to generate a flow of air in thedirection of the heat-exchange tubes 4.

The heat-exchange tubes 4 and the ventilation tubes 8 may all beparallel to one another, as shown in FIG. 1. The rows of ventilationtubes 8 and of heat-exchange tubes 4 are therefore themselves parallel.Moreover, the ventilation tubes 8 may be disposed so that each of themis opposite a heat-exchange tube 4.

The number of ventilation tubes 8 is matched to the number ofheat-exchange tubes 4. For example, for a conventional heat exchanger 1,the ventilation device 2 may comprise for example at least tenventilation tubes 8, preferably at least 15 ventilation tubes 8, morepreferably at least 24 ventilation tubes 8 and/or at most 50 ventilationtubes 8, preferably at most 36 ventilation tubes 8, more preferably atmost 30 ventilation tubes 8. The heat exchanger 1 may for exampleinclude between 60 and 70 heat-exchange tubes 4.

The tubes and the number of ventilation tubes 8 of the ventilationdevice 2 may be such that a minimum air passage section between thetubes of the ventilation device, defined in a plane substantiallyperpendicular to the flow of air through the heat exchanger 1, isbetween 25 and 50% of the surface area, defined in a plane perpendicularto the flow of air through the heat exchanger, between two endheat-exchange tubes.

The front surface area of the ventilation tubes 8, measured in a planesubstantially perpendicular to the flow of air through the heatexchanger 1, is preferably less than 85% of the front surface areaoccupied by the heat-exchange tubes 4.

Moreover, in order to limit the volume occupied by the heat-exchangemodule comprising the heat exchanger 1 and the ventilation device 2,whilst obtaining heat exchanger performance similar to that of a helicalventilation device, the row of ventilation tubes 8 may be disposed at adistance less than or equal to 150 mm from the row of heat-exchangetubes 4, preferably less than or equal to 100 mm. This distance ispreferably greater than or equal to 5 mm, preferably greater than 40 mm.In fact, too great a distance between the ventilation tubes 8 and theheat-exchange tubes 4 risks not allowing homogeneous mixing with theinduced flow of air of the flow of air ejected from the ventilationtubes 8. A non-homogeneous mixture does not enable homogeneous coolingof the heat-exchange tubes 4 and induces high head losses. Too great adistance risks not enabling placement of the assembly formed by theventilation device and the heat-exchange device in a motor vehiclewithout necessitating appropriate design of the engine block and/orother units of the motor vehicle present in the vicinity of theheat-exchange module.

Likewise, and still to limit the volume occupied by the heat-exchangemodule, the height of the row of ventilation tubes 8 (the term heightreferring here to the dimension corresponding to the direction in whichthe ventilation tubes 8 are aligned) may be made substantially equal toor less than the height of the row of heat-exchange tubes 4. Forexample, the height of the row of heat-exchange tubes 4 being 431 mm,the height of the row of ventilation tubes 8 may be made substantiallyequal to or less than that value.

The ventilation device 2 further comprises a device, not visible in FIG.1, for feeding air to the ventilation tubes 8 via an air inlet manifold12, preferably via two air inlet manifolds 12.

The means for propulsion of air consist for example of a turbomachine,feeding the two air inlet manifolds 12, disposed at each of the ends ofthe ventilation device 1, via a respective port 13. In the example shownin FIG. 1, the ports 13 are substantially in the middle of the air inletmanifolds 12. Additionally or alternatively, there are ports 13 at alongitudinal end 12 a, 12 b of each inlet manifold 12. Alternatively, aturbomachine may feed a single inlet manifold 12 and not two. Also, oneor more turbomachines may be employed to feed each air inlet manifold 12or all the air inlet manifolds 12.

In accordance with another embodiment, the turbomachine(s) is/are alsoreceived in one or in each air inlet manifold 12.

However, here the air propulsion means are spaced from the ventilationtubes 8 by the air inlet manifolds 12. The or each turbomachine need notbe directly adjacent to the air inlet manifolds 12.

Each air inlet manifold 12 may for example be tubular. In the FIG. 1embodiment the air inlet manifolds 12 extend in the same direction,which here is perpendicular to the lengthwise (or longitudinal)direction of the heat-exchange tubes 4 and ventilation tubes 8.

As can be seen in FIG. 1, the air inlet manifold 12 comprises aplurality of air ejection orifices 14 each produced at one end of arespective tubular portion, each air ejection orifice 14 being connectedto a single ventilation tube 8, and more particularly to the end of theventilation tube 8.

In accordance with the example from FIGS. 1 and 2, each ventilation tube8 has a plurality of openings 16 for the passage of a flow of air F2through the tube 8. The openings 16 of the ventilation tubes 8 aresituated outside the air manifolds 12. To be more precise, here theopenings 16 are oriented substantially in the direction of the heatexchanger 1, and to be even more precise, substantially in the directionof the heat-exchange tubes 4, the slots 16 being for example disposedfacing the heat-exchange tubes 4 or fins accommodated between theheat-exchange tubes.

Each ventilation tube 8 opens into a different port 14 of each manifold12. Each air manifold 12 therefore has as many ports 14 as it receivesventilation tubes 8, a ventilation tube 8 being received in each of theports 14 of the air manifold 12. This enables more homogeneousdistribution in the various ventilation tubes 8 of the flow of airthrough each air manifold 12.

In this instance, each air manifold 12 has a hollow shape, for example asubstantially cylindrical shape, even more particularly a substantiallycylindrical shape with a rectilinear axis. Apart from the ports 14 intowhich the ventilation tubes 8 open, at their ends, each air manifold 12further includes one or more vents 13 intended to be in fluidcommunication with a turbomachine (not represented in the figures) tocreate a flow of air in each manifold 12. Each manifold 12 then enablesdistribution of that flow of air into the various ventilation tubes 8.In accordance with different variants, each air manifold 12 may be influid communication with one or more of its own turbomachines (that isto say in fluid communication only with one of the two air manifolds 12)or, to the contrary, the air manifolds 12 may be in fluid communicationwith the same turbomachine or a plurality of common turbomachines (thatis to say each turbomachine is in fluid communication with each of themanifolds 12).

Each air manifold 12 advantageously has no openings other than the ports14 and the vent or vents 13 mentioned above. In particular, the manifold12 preferably includes no openings oriented in the direction of the heatexchanger 1, which in the present instance would enable ejection of someof the flow of air through the air manifold 12, directly in thedirection of the heat exchanger 1, without passing through at least aportion of a ventilation tube 8. All of the flow of air created by theturbomachine(s) and passing through the air manifold(s) 12 is thereforedistributed between substantially all of the ventilation tubes 8. Thisalso enables a more homogeneous distribution of this flow of air.

It is to be noted here that an advantage of the cooling module 10 fromFIG. 1 is the possibility of remotely siting the turbomachines(s) at adistance from the ventilation tubes 8, in particular via the inletmanifolds 12, and, where applicable, an appropriate aeraulic circuitestablishing fluid communication between the vent(s) 13 of the airmanifold(s) 12 with one or more turbomachines.

Moreover, the air manifold(s) 12 and the ventilation tubes 8 areconfigured here so that a flow of air through the air manifold(s) 12 isdistributed between the various ventilation tubes 8, travels through thevarious ventilation tubes 8, and is ejected via the openings 16. Theopenings 16 being disposed facing the heat exchanger 1, a flow of air F2is therefore ejected via the openings 16 and passes through the heatexchanger 1.

However, it is to be noted that the flow of air F1 through the heatexchanger 1 may be substantially different from the flow of air F2ejected via the openings. In particular, the flow of air F1 may include,in addition to the flow of air F2, a flow of surrounding air created bythe movement of the motor vehicle when in motion.

Except at their ends forming air inlets, which have a substantiallycircular cross section, the ventilation tubes 8 preferably have aconstant substantially oblong cross section, interrupted by the openings16, as shown in FIG. 2.

The choice of this shape enables easy production of the ventilationtubes 8 and imparts high mechanical strength to the ventilation tubes 8.In particular, ventilation tubes 8 of this kind may be obtained bybending an aluminum sheet for example, but also by molding, overmolding,or by 3D printing a metal or a plastic.

To be more precise, in the example from FIGS. 1 and 2, the cross sectionof the ventilation tubes 8 has a substantially elliptical shape theminor axis of which corresponds to the height of the ventilation tubes 8and the major axis to the width of the ventilation tubes 8 (the termsheight and width must be understood relative to the FIG. 2 orientation).For example, the minor axis h of the ellipse is approximately 11 mmlong.

To increase the flow of air F2 ejected toward the heat exchanger 1through the openings 16, the openings 16 consist of slots formed in thewalls 17 of the ventilation tube 8, those slots 16 extending in thelengthwise direction of the ventilation tube 8. This slot shape enablesan air passage with large dimensions to be constituted, whilstmaintaining a satisfactory mechanical strength of the ventilation tubes8. To obtain the greatest possible passage of air, the openings 16therefore extend over a great part of the length of the ventilation tube8, preferably over a total length corresponding to at least 90% of thelength of the ventilation tube 8.

The openings 16 are delimited by guide lips 18 projecting from the wall17 of the ventilation tube 8.

Because they project from the wall 17 of each ventilation tube 8, theguide lips 18 make it possible to guide the air ejected via the opening16 from inside the ventilation tube 8 in the direction of the heatexchanger 1.

The guide lips 18 are preferably plane and substantially parallel. Forexample, they are spaced from one another by a distance of approximately5 mm and have a width (the term width having to be considered in thesense of the FIG. 4 orientation), between 2 and 5 mm inclusive. Theguide lips 18 advantageously extend the whole length of each opening 16.

The guide lips 18 are preferably in one piece with the ventilation tube8. The guide lips 18 are for example obtained by bending a wall 17 ofthe ventilation tube 8.

Moreover, the openings 16 are also delimited, in the lengthwisedirection of the ventilation tubes 8, by elements 20 for reinforcing theventilation tubes 8. The reinforcing elements 20 enable the width of theopenings 16 to be kept constant. Here this is achieved by virtue of thefact that the reinforcing elements extend between the two guide lips 18extending on either side of each opening 16. The reinforcing elements 20preferably extend in a plane substantially normal to the lengthwisedirection of the ventilation tubes 8, in order to maintain as large aspossible a section of the openings 16 enabling the passage of the flowof air F2. The reinforcing elements 20 are advantageously regularlydistributed over the length of the ventilation tubes 8. In the exampleshown in FIG. 3, each ventilation tube 8 includes seven reinforcingelements 20. Of course, that number is in no way limiting on theinvention.

Alternatively, the cross section of the ventilation tubes 8 issubstantially circular, interrupted by the openings 16. For example, thediameter of the circle interrupted by the openings 16 is approximately11 mm.

Moreover, FIG. 3 shows diagrammatically a first example of an air inletmanifold 12 of the ventilation device 2 shown in FIG. 1.

This first example 100 of an air inlet manifold is substantiallyT-shaped with an inlet port 13 intended to be in fluid communicationwith an air propulsion device to feed with a flow of air, via the airinlet manifold, the various ventilation tubes 8. The first example 100of an air inlet manifold has a substantially constant circular section.

Remarkably, the air inlet manifold 200 in accordance with the secondexample shown in FIG. 4 comprises air guides in the form of means 104for distributing the flow of air entering the manifold via the inletport 13 toward the outlet ports 14. These distribution means 104 enablemore homogeneous distribution of the flow of air entering the manifold12 between the various outlet ports 14.

Here, these distribution means 104 essentially comprise five rectilinearwalls 106 diverging in the direction from the inlet port 13 to theoutlet ports 14. These rectilinear walls 106 guide the incoming flow ofair, enable limitation of the head losses of the flow of air through themanifold 12, and more particularly enable reduction of the passagesection.

In FIG. 5, the inlet manifold 12 is a dual inlet manifold including twoseparate halves 12 ₁, 12 ₂. Here these two halves 12 ₁, 12 ₂ areidentical. The two halves 12 ₁, 12 ₂, are substantially identical to themanifold 200 from FIG. 4. However, here, each half 12 ₁, 12 ₂ of themanifold 300 includes only three divergent rectilinear walls 106 by wayof means 104 for distributing the flow of air entering the manifold 300via the ports 13 ₁, 13 ₂, toward the outlet ports 14.

The manifold 400 in accordance with the FIG. 6 example is also a dualmanifold comprising two halves 12 ₁, 12 ₂. Here those halves aresymmetrical. Here the ports 13 ₁, 13 ₂ are disposed at the longitudinalends 12 a, 12 b of the inlet manifold 400. This enables production of amore compact heat-exchange module. Consequently, each half 12 ₁, 12 ₂,of the air inlet manifold 400 is bent. Each half 12 ₁, 12 ₂ of the airinlet manifold 400 is provided with means 104 for distributing the flowof air entering the air inlet manifold 400 via the inlet ports 13 ₁, 13₂ toward the outlet ports 14. Here, these means 104 take the form of twowalls 106. Here, the walls are not rectilinear. To the contrary, the twowalls 106 are curved. The walls 106 therefore enable improved guidanceof the flow of air entering via the inlet port 13 ₁, 13 ₂ toward theoutlet ports 14.

Over and above this, the manifold 400 from FIG. 6 is provided with airguides in the form of deflectors 402 in the vicinity of the ports 14.These deflectors 402 are provided by curved walls that extend in thevicinity of the ports 14 in a manner perpendicular to those ports 14.These deflectors 402 therefore enable better guidance of the flow of airin the direction of the ports 14, thereby limiting head losses. Thedeflectors 402 advantageously divert the flow of air in a directionsubstantially normal to the section of the ports 14, in the vicinity ofthose ports 14. The deflectors 402 are for example rectilinear, curvedor bent (that is to say with rectilinear portions) walls.

The manifold 500 from FIG. 7 is also a dual air inlet manifold,comprising two symmetrical halves 12 ₁, 12 ₂. The inlet ports 13 ₁, 13 ₂are also situated at the longitudinal ends 12 a, 12 b of the air inletmanifold 500 in order to limit the overall width thereof. The air inletmanifold 500 is bent.

The manifold 500 is provided with nine walls 106 in each half 12 ₁, 12 ₂forming means 104 for distribution of the flow of air entering the airinlet manifold 500 via the inlet ports 13 ₁, 13 ₂ toward the outletports 14. In the vicinity of the ports 13 ₁, 13 ₂ these walls 106 extendsubstantially in the direction in which the ports 13 ₁, 13 ₂ extend. Tothe contrary, in the vicinity of the ports 14, the walls 106 extendperpendicularly to the section of the ports 14. Thus the walls 106extend in two perpendicular directions in the vicinity of the inlet port13 ₁, 13 ₂ and in the vicinity of the ports 14. The walls 106 thereforeform means 104 for distribution of the flow of air and also thedeflectors 402.

Other forms of means 104 for distribution of the flow of air areavailable to the person skilled in the art. The shape of the walls maytherefore be different. In particular, the walls 106 may be rectilinear,have rectilinear portions or be curved.

Likewise, in the examples from FIGS. 4 to 7, the walls 106 may be in onepiece with the air inlet manifold or the walls 106 may be producedseparately from the air inlet manifold and then fixed to it.

The walls 106 and/or the deflectors 402 may advantageously be made of anelectrically conductive material. It is therefore possible to pass anelectric current in the walls 106 and/or in the deflectors 402 toproduce heat by the Joule effect. The heat produced may in particular beused to heat the flow of air.

Moreover, the number of walls 106 described is not limiting on theinvention. However, it was found that the best results were obtainedwhen the number of walls 106 per air inlet manifold or per half airinlet manifold was chosen in accordance with the ratio of the total areaof the air flow inlet to the total area of the air flow outlets. Thetotal air flow inlet area means the area of the cross section of theinlet port or the sum of the input port cross section areas. The totalarea of the outlets means the sum of the areas of the cross sections ofthe outlet ports. In particular, the number of partitions may be zero ifthe ratio of the total inlet area of the manifold to the total area ofthe outlets is greater than 1.5. The number of partitions may be equalto 3 if the ratio of the total inlet area of the manifold to the totalarea of the outlets is between 1 and 1.5 inclusive. And the number ofpartitions may be equal to 5 or more if the ratio of the total inletarea of the manifold to the total area of the outlets is less than 1.

The use of air guides in the form of means for distributing the flow ofair and/or of deflectors is independent of the shape of the ventilationtubes 8. Hereinafter there are described examples of ventilation tube 8shapes that may be employed in the ventilation device 2.

Hereinafter, the ventilation tubes 8 are referred to as aerodynamictubes 8. It may be noted here that the shape of the ventilation tubes 8is a priori independent of the configuration of the air inlet manifolds.

An aerodynamic tube 8 has over a portion of, preferably oversubstantially all of, its length a cross section as shown in FIG. 8 witha leading edge 37, a trailing edge 38 opposite the leading edge 37 andhere disposed facing the heat-exchange tubes 4 and first and secondprofiles 42, 44 each extending between the leading edge 37 and thetrailing edge 38. The leading edge 37 is for example defined as thepoint at the front of the section of the aerodynamic tube 8 at which theradius of curvature of the section is minimum. The front of the sectionof the aerodynamic tube 8 may for its part be defined as the portion ofthe section of the aerodynamic tube 8 that is opposite—that is to sayfaces—the heat exchanger 1. Likewise, the trailing edge 38 may bedefined as the point at the rear of the section of the aerodynamic tube8 at which the radius of curvature of the section is minimum. The rearof the section of the aerodynamic tube 8 may be defined for example asthe portion of the section of the aerodynamic tube 8 that faces the heatexchanger 1.

The distance c between the leading edge 37 and the trailing edge 38 isfor example between 16 mm and 26 mm inclusive. Here this distance ismeasured in a direction perpendicular to the direction of alignment ofthe row of aerodynamic tubes 8 and to the longitudinal direction of theaerodynamic tubes 8.

In the FIG. 8 example the leading edge 37 is free. Also in this figurethe leading edge 37 is defined over a parabolic portion of the sectionof the aerodynamic tube 8.

The aerodynamic tube 8 shown in FIG. 8 further includes at least oneopening 40 for ejecting a flow of air passing through the aerodynamictube 8 to the outside of the aerodynamic tube 8 and of the air inletmanifold 12, in particular substantially in the direction of the heatexchanger 1. The opening or each opening 40 is for example a slot in anexternal wall 41 of the aerodynamic tube 8, the slot(s) extending forexample in the lengthwise direction of the aerodynamic tube 8 in whichit is or they are produced. The total length of the opening(s) 40 may begreater than 90% of the length of the aerodynamic tube. Each opening 40is separate from the ends of the aerodynamic tube 8, via which theaerodynamic tube 8 opens into an air manifold 12. Each opening 40 ismoreover outside the air inlet manifold 12. The slot shape enablesproduction of an air passage of large size in the direction of the heatexchanger 1 without excessively reducing the mechanical strength of theaerodynamic tubes 8.

Hereinafter there is described only one opening 40 on the understandingthat each opening 40 of the aerodynamic tube 8 may be identical to theopening 40 described.

The opening 40 is for example disposed in the vicinity of the leadingedge 37. In the FIG. 8 example, the opening 40 is on the first profile42. In this example the second profile 44 has no opening(s) 40. Theopening 40 in the first profile 42 is configured so that the flow of airejected via the opening 40 flows along at least a part of the firstprofile 42.

The aerodynamic tubes 8 of the ventilation device 2 may be orientedalternately with the first profile 42 or the second profile 44 orientedupwards. Two adjacent aerodynamic tubes 8 are therefore alternately suchthat their first profiles 42 are face-to-face or, to the contrary, theirsecond profiles 44 are face-to-face. The distance between two adjacentaerodynamic tubes 8 the second profiles 44 of which are face-to-face isless than the distance between two adjacent aerodynamic tubes 8 thefirst profiles 42 of which are face-to-face. The pitch between twoadjacent aerodynamic tubes or the distance between the center of thegeometrical section of the first aerodynamic tube 8 at the center of thegeometrical section of a second aerodynamic tube 8, such that the firstprofile 42 of the first aerodynamic tube 8 is face-to-face with thefirst profile 42 of the second aerodynamic tube 8, measured in thedirection of alignment of the aerodynamic tubes 8, is greater than orequal to 15 mm, preferably greater than or equal to 20 mm, and/or lessthan or equal to 30 mm, preferably less than or equal to 25 mm

For each pair of aerodynamic tubes 8 the openings 40 of which areface-to-face, the flows of air ejected via these openings 40 thereforecreate an air passage into which some of the surrounding air, termedinduced air, is entrained by aspiration.

It is to be noted here that the flow of air ejected via the openings 40travels along at least a portion of the first profile 42 of theaerodynamic tube 8, for example by the Coanda effect. Exploiting thisphenomenon, it is possible, thanks to the drawing of the surrounding airinto the air passage created, to obtain a flow rate of air sent towardthe heat-exchange tubes identical to that generated by a helical fan butconsuming less energy.

In fact, the flow of air sent toward the row of heat-exchange tubes 4 isthe sum of the flow of air ejected via the slots and the induced flow ofair. It is therefore possible to employ a turbomachine of reduced powercompared to a conventional helical fan, as generally employed in thecontext of this kind of heat-exchange module.

A first profile 42 having a Coanda surface moreover makes it possiblenot to have to orient the openings 40 directly in the direction of theheat-exchange tubes 4 and therefore to limit the overall size of theaerodynamic tubes 8. It is therefore possible to maintain a greaterpassage section between the aerodynamic tubes 8, which encourages theformation of a higher induced air flow rate.

In FIG. 8 the opening 40 is delimited by lips 40 a, 40 b. The distance ebetween the lips 40 a, 40 b, which defines the height of the opening 40may be greater than or equal to 0.3 mm, preferably greater than or equalto 0 5 mm, more preferably greater than or equal to 0.7 mm and/or lessthan 2 mm, preferably less than or equal to 1.5 mm, more preferably lessthan 0.9 mm, even more preferably less than or equal to 0.7 mm. Theheight of the slot is the dimension of that slot in the directionperpendicular to its length. The lower the height of the slot 40, thegreater the speed of the flow of air ejected via that slot. A high speedof the injected flow of air is reflected in a high dynamic pressure.This dynamic pressure is then converted into static pressure in the areamixing the flow of air ejected via the slot 40 and the induced flow ofair. This static pressure enables the head losses caused by the presenceof the heat exchanger downstream of the ventilation device to beovercome, in order to ensure an appropriate flow of air through the heatexchanger. These head losses caused by the heat exchanger vary inparticular as a function of the pitch of the heat-exchange tubes and ofthe pitch of the fins of the heat exchanger, and a function of thenumber of heat-exchange modules that can be superposed in the heatexchanger. However, too low a slot height induces high head losses inthe ventilation device, which implies using one or more higher ratedpropulsion devices. This can generate an overcost and/or create anoverall size incompatible with the room available in the vicinity of theheat-exchange module in the motor vehicle.

Here the outer lip 40 a consists of the extension of the wall of theaerodynamic tube 8 defining the leading edge 37. The lower lip 40 bconsists of a curved portion 50 of the first profile 42. One end 51 ofthe inner lip 40 b may be extended, as shown in FIG. 11, in thedirection of the second profile 44, beyond a plane L normal to the freeend of the outer lip 40 a. In other words, the end 51 of the inner lip40 b may be extended, in the direction of the leading edge 37, beyondthe plane L normal to the free end of the outer lip 40 a. The end 51 canthen contribute to directing the flow of air circulating in theaerodynamic tube 8 toward the opening 40.

The opening 40 of the aerodynamic tube 8 may be configured so that aflow of air circulating in that aerodynamic tube 8 is ejected via thatopening 40, flowing along the first profile 42 substantially as far asthe trailing edge 38 of the aerodynamic tube 8. The flow of the flow ofair along the first profile 42 may result from the Coanda effect.Remember than the Coanda effect is an aerodynamic phenomenon reflectedin the fact that a fluid flowing along a surface at a small distancefrom the latter tends to be flush with it, or even attached to it.

To this end, here, the maximum distance h between the first profile 42and the second profile 44, measured in a direction of alignment of theaerodynamic tubes 8, is downstream of the opening 40. The maximumdistance h may be greater than 10 mm, preferably greater than 11 mmand/or less than 20 mm, preferably less than 15 mm Here, for example,the maximum distance h is substantially equal to 11.5 mm Too small aheight h may generate high head losses in the aerodynamic tube 8, whichcould necessitate use of a more powerful and therefore more bulkyturbomachine. For the same value of the distance between the aerodynamictubes 8, measured in the direction of alignment of the aerodynamictubes, too great a height h limits the passage section between theaerodynamic tubes for the induced flow of air. The total flow of airdirected toward the heat exchanger is then also reduced.

Here the first profile 42 includes a convex portion 50 the summit ofwhich defines the point of the first profile 42 corresponding to themaximum distance h. The convex portion 50 may be disposed downstream ofthe opening 40 in the direction of ejection of the flow of air. Inparticular, the convex portion 50 may be contiguous with the inner lip40 b delimiting the opening 40.

Downstream of the convex portion 50 in the direction of ejection of saidflow of air via the opening 40, the first profile 42 of the aerodynamictube 8 of the FIG. 8 example includes a substantially rectilinear firstportion 52. In the example shown in FIG. 8, the second profile 44includes a substantially rectilinear portion 48 preferably extendingover a majority of the length of the second profile 44. In the FIG. 8example the length 1 of the rectilinear first portion 52, measured in adirection perpendicular to the longitudinal direction of the aerodynamictube 8 and to the direction of alignment of the row of aerodynamictubes, may be greater than or equal to 30 mm, preferably greater than orequal to 40 mm, and/or less than or equal to 50 mm A relatively greatlength of this rectilinear first portion is required in particular toensure the guidance of the flow of air ejected from the opening 40,which enables greater aspiration of air. The length of this rectilinearfirst portion is however limited by virtue of the corresponding overallsize of the ventilation device and the consequences thereof forpackaging the ventilation device or the heat-exchange module.

In this case, the rectilinear first portion 52 of the first profile 42and the rectilinear portion 48 of the second profile 44 may form anon-flat angle θ. The resulting angle θ may in particular be greaterthan or equal to 5°, and/or less than or equal to 20°, more preferablysubstantially equal to 10°. This angle of the rectilinear first portion52 relative to the rectilinear portion 48 of the second profile 44 makesit possible to accentuate the expansion of the flow of air ejected viathe opening 40 and subjected to the Coanda effect, forcing it to followthe first profile 42, this accentuated expansion making it possible toincrease the induced flow of air. Too great an angle θ however riskspreventing the production of the Coanda effect, so that the flow of airejected via the opening 40 risks not following the first profile 42 and,consequently, not being oriented correctly in the direction of the heatexchanger 2.

As shown in FIG. 8, the first profile 42 may include a rectilinearsecond portion 38 a downstream of the rectilinear first portion 52 inthe direction of ejection of the flow of air, the rectilinear secondportion 38 a extending substantially parallel to the rectilinear portion48 of the second profile 44. The first profile 42 may also include arectilinear third portion 54 downstream of the rectilinear secondportion 38 a of the first profile 42. The rectilinear third portion 54may form a non-flat angle with the rectilinear portion 48 of the secondprofile 44. As shown, the rectilinear third portion 54 may extendsubstantially as far as a rounded edge connecting the rectilinear thirdportion 54 of the first profile 42 and the rectilinear portion 48 of thesecond profile 44. The rounded edge may define the trailing edge 38 ofthe cross section of the aerodynamic tube 8.

In the FIG. 8 example, the rectilinear portion 48 of the second profile44 extends over the majority of the length c of the cross section. Thislength c is measured in a direction perpendicular to the longitudinaldirection of the aerodynamic tubes 8 and to the direction of alignmentof the row of aerodynamic tubes 8. In the FIG. 11 example this directionsubstantially corresponds to the direction of flow of the induced flowof air. In this first embodiment the length c of the cross section (orthe width of the aerodynamic tube 8) may be greater than or equal to 50mm and/or less than or equal to 70 mm, preferably substantially equal to60 mm. In fact, the inventors have found that a relatively great lengthof the cross section of the aerodynamic tube enables more effectiveguidance of the flow of air ejected via the opening 40 and the inducedflow of air, which is mixed with that ejected flow of air. However, toogreat a length of the cross section of the aerodynamic tube 8 gives riseto a problem with packaging the ventilation device 2. In particular, theoverall size of the heat exchanger module can then be too large comparedto the room that is available in the motor vehicle in which it isintended to be mounted. The packaging of the heat exchanger module or ofthe ventilation device may also be problematic in this case.

Moreover, as shown in FIG. 8, the rectilinear second portion 38 a of thefirst profile 42 and the portion 38 b of the rectilinear portion 48 ofthe second profile 44 that faces it are parallel. For example, thedistance f between this rectilinear second portion 38 a and the portion38 b of the rectilinear portion 48 of the second profile 44 may begreater than or equal to 2 mm and/or less than or equal to 10 mm,preferably less than or equal to 5 mm

FIG. 8 further shows that the cross section (or geometrical section) ofthe aerodynamic tube 8 delimits a passage section S for the flow of airthrough the aerodynamic tube 8. Here this passage section S is definedby the walls of the aerodynamic tube 8 and by the segment extending inthe direction of alignment of the aerodynamic tubes 8 between the secondprofile 44 and the end of the end 51 of the inner lip 40 b. This passagesection may have an area greater than or equal to 150 mm², preferablygreater than or equal to 200 mm², and/or less than equal to 700 mm²,preferably less than or equal to 650 mm². A passage section of the flowof air in the aerodynamic tube 8 makes it possible to limit head lossesthat would have the consequence of increasing the size of theturbomachine employed to produce a required flow rate of air ejected viathe opening 40. However, a large passage section induces a large overallsize of the aerodynamic tube 8. With a fixed pitch of the aerodynamictubes, a greater passage section therefore risks compromising thepassage section of the induced flow of air between the aerodynamic tubes8, thus making it impossible to obtain a satisfactory total flow rate ofair directed toward the heat-exchange tubes 4.

To obstruct as little as possible the flow of air toward theheat-exchange tubes 4 and the fins, the ventilation device 2 providedwith aerodynamic tubes 8 of this kind is advantageously disposed so thateach aerodynamic tube 8 is face-to-face with the front face 4 fconnected the first plane wall 4 a and the second plane wall 4 b of acorresponding heat-exchange tube 4. More particularly, the trailing edge38 of each aerodynamic tube 8 is contained within the volume delimitedby the first and second longitudinal plane walls of the correspondingheat exchange tube 4.

The rectilinear second portion 38 a of the first profile and therectilinear portion 48 of the second profile 44 are preferablyrespectively contained in the same plane as the first longitudinal planewall and the second longitudinal plane wall of the correspondingheat-exchange tube 4.

In particular, the distance f separating the rectilinear second portion38 a of the first profile 42 and the portion 38 b of the rectilinearportion 48 of the second profile 44 facing it is substantially equal tothe distance separating the first longitudinal wall and the secondlongitudinal wall of the heat-exchange tube 4 face-to-face with whichthe aerodynamic tube 8 is disposed. For example, this distance f isgreater than or equal to 2 mm and/or less than or equal to 10 mm,preferably less than or equal to 5 mm

In other embodiments the distance f separating the rectilinear secondportion 38 a of the first profile 42 and the portion 38 b of therectilinear portion 48 of the second profile 44 facing it maynevertheless be less than the distance separating the first longitudinalwall and the second longitudinal wall of the heat-exchange tubeface-to-face with which the aerodynamic tube 8 is disposed.

Two heat-exchange tubes 4 may be contained in the volume delimited bythe air passage defined by two adjacent aerodynamic tubes 8.Nevertheless, only one heat-exchange tube 4 or three or fourheat-exchange tubes 4 being contained within that volume may beenvisaged. Conversely, an aerodynamic tube 8 disposed face-to-face witheach heat-exchange tube 4 may be envisaged.

In the examples from FIGS. 9, 10 and 11 the aerodynamic tubes 8 aresubstantially rectilinear, parallel to one another and aligned in such amanner as to form a row of aerodynamic tubes 8. However, the first andsecond profiles 42, 44 of each aerodynamic tube 8 are, in theseexamples, symmetrical with respect to a plane C-C, or chord plane,passing through the leading edge 37 and the trailing edge 38 of eachaerodynamic tube 8.

As the first and second profiles 42, 44 are symmetrical, each of theseprofiles 42, 44 is provided with an opening 40. At least one firstopening 40 is therefore produced on the first profile 42, which isconfigured so that a flow of air leaving the first opening 42 flowsalong at least a portion of the first profile 42. Likewise, at least onesecond opening 40 is present on the second profile 44, which isconfigured so that a flow of air leaving the second opening 40 flowsalong at least a portion of the second profile 44. As in the FIG. 8example, this may be achieved here by exploiting the Coanda effect.

For the same reasons as given for the FIG. 8 example, the distance cbetween the leading edge 37 and the trailing edge 38 may also, in theseexamples, be greater than or equal to 50 mm and/or less than or equal to80 mm. In particular, the length c may be equal to 60 mm.

The openings 40 are analogous to those of the FIG. 8 example. Inparticular, the distance e separating the inner lip 40 b and the outerlip 40 a of each opening 40 may be greater than or equal to 0.3 mm,preferably greater than or equal to 0 5 mm, more preferably greater thanor equal to 0.7 mm, and/or less than or equal to 2 mm, preferably lessthan or equal to 1.5 mm, more preferably less than or equal to 0.9 mmand yet further preferably less than or equal to 0.7 mm

The fact that the profiles 42, 44 are symmetrical with respect to thechord plane C-C passing through the leading edge 37 and the trailingedge 38 of the aerodynamic tube 8 makes it possible to limit theobstruction of the flow of air between the ventilation device 2 and theheat-exchange tubes 4 whilst creating more air passages in the volumeavailable in front of the heat-exchange tubes 4.

In other words, in contrast to the embodiment from FIG. 8, an airpassage drawing in surrounding air is created between each pair ofadjacent aerodynamic tubes 8 produced in accordance with any of FIGS. 9to 11.

The pitch between two adjacent aerodynamic tubes 8 may, in this case, begreater than or equal to 15 mm, preferably greater than or equal to 20mm, more preferably greater than or equal to 23 mm and/or less than orequal to 30 mm, preferably less than or equal to 25 mm, more preferablyless than or equal to 27 mm. In fact, if the pitch between theaerodynamic tubes 8 is smaller, the induced air flow is limited by asmall passage section between the aerodynamic tubes. On the other hand,if the pitch is too great, the ejected flow of air does not make itpossible to create an induced flow of air over all of the pitch betweenthe adjacent aerodynamic tubes.

The pitch between two adjacent aerodynamic tubes 8 may in particular bedefined as the distance between the center of the cross section of twoadjacent aerodynamic tubes 8 or, more generally, as the distance betweena reference point on a first aerodynamic tube 8 and the pointcorresponding to the reference point on the nearest aerodynamic tube 8.The reference point may in particular be one of the following: theleading edge 37, the trailing edge 38 or the summit of the convexportion 50.

The distance between the aerodynamic tubes 8 and the heat-exchange tubes4 may in particular be made greater than or equal to 5 mm, preferablygreater than or equal to 40 mm, and/or less than or equal to 150 mm,preferably less than or equal to 100 mm. In fact, the peak speed of thespeed profile of the air in the vicinity of the profile tends todecrease in the direction away from the opening 40 in the aerodynamictube. An absence of any peak reflects a homogeneous mixture of the airflow ejected via the opening 40 and of the induced air flow. It ispreferable for homogeneous mixing of this kind to be obtained before theflow of air reaches the aerodynamic tubes. In fact, a heterogeneous flowof air incident on the heat-exchange tubes does not enable optimumcooling of the heat-exchange tubes and induces greater head losses.However, the distance between the aerodynamic tubes and theheat-exchange tubes is preferably contained in order to limit theoverall size of the cooling module.

In the example shown in FIG. 9 the first and second profiles 42, 44 ofthe aerodynamic tube 8 converge toward the trailing edge 38 so that thedistance separating the first and second profiles 42, 44 decreasesstrictly in the direction of the trailing edge 38 from a point on thosefirst and second profiles 42, 44 corresponding to the maximum distance hbetween those two profiles, these points on the first and secondprofiles 42, 44 being downstream of the openings 40 in the direction offlow of the flow of air ejected via the opening 40. Each of the firstand second profiles 42, 44 preferably forms an angle between 5 and 10°with the chord C-C of symmetry of the cross section of the aerodynamictube 8.

Because of this, in contrast to the FIG. 8 example, the aerodynamicprofile in FIG. 9 does not comprise a portion delimited by first andsecond parallel opposite plane walls. This has the advantage of limitingdrag along the aerodynamic profile of the aerodynamic tube 8.

For example, the maximum distance h between the first profile 42 and thesecond profile 44 may be greater than or equal to 10 mm and/or less thanor equal to 30 mm. In particular, this maximum distance h may be equalto 11.5 mm. In the example shown in FIGS. 12 to 14, this distancebecomes zero at the level of the trailing edge 38.

In the example shown in FIG. 10, the trailing edge 38 is formed by thesummit joining two symmetrical rectilinear portions 60 of the firstprofile 42 and the second profile 44 of each aerodynamic tube 8. Inaccordance with the FIG. 8 variant the trailing edge 38 is the point ofthe cross section of the aerodynamic tube 8 situated closest to the heatexchanger. In other words, the angle α formed by the two rectilinearportions 60 is less than 180°, in particular less than 90°.

On the other hand, in the FIG. 11 variant, the trailing edge 38 isdisposed between the two rectilinear portions 38 a, 38 b of the firstand second profiles 42, 44. In other words, the angle α formed by therectilinear portions 60 is here greater than 90°, in particular greaterthan 180°.

The invention is not limited to the embodiments described and otherembodiments will be clearly apparent to the person skilled in the art.In particular, the various examples may be combined, provided that theyare not contradictory. For example, the air guides may comprise, in anindependent or complementary manner, the means for distributing the flowof air and/or deflectors.

1. A ventilation device configured to generate a flow of air through amotor vehicle heat exchanger, the ventilation device comprising: aplurality of ducts; at least one air manifold including at least one airflow inlet and ports, each duct opening at one of the ends thereof intoa port separate from the air manifold, each duct having at least oneopening for the passage of a flow of air through said duct, the openingbeing separate from the ends of the corresponding duct, the openingbeing situated outside the at least one air manifold, wherein the atleast one air manifold is provided with air guides configured to guidethe flow of air passing through the air manifold.
 2. The ventilationdevice as claimed in claim 1, in which the air guides comprise means fordistributing the flow of air entering the manifold via said at least oneair flow inlet toward the ports.
 3. The ventilation device as claimed inclaim 2, in which the distribution means include partitions inside theat least one air manifold.
 4. The ventilation device as claimed in claim3, in which, for each air manifold: the number of partitions is zero ifthe ratio of the area of the inlet of the manifold to the total area ofthe ports is greater than 1.5, and/or the number of partitions is equalto three if the ratio of the area of the inlet of the manifold to thetotal area of the ports is between 1 and 1.5 inclusive; and/or thenumber of partitions is equal to 5 or more when the ratio of the area ofthe inlet of the manifold to the total area of the ports is less than 1.5. The ventilation device as claimed in claim 2, in which at least onepartition extends, in the vicinity of the air flow inlet, in a firstdirection, said at least one partition extends, in the vicinity of theports, in a second direction, and the first and second directions aresubstantially perpendicular.
 6. The ventilation device as claimed inclaim 1, in which the air guides comprise, in the vicinity of the ports,deflectors adapted to deviate the flow of air to the vicinity of theports, so that the flow of air passing through the ports is directlysubstantially in a direction normal to the section of the ports.
 7. Theventilation device as claimed in claim 6, in which each deflector isrectilinear, partly rectilinear or curved.
 8. The ventilation device asclaimed in claim 6, in which the deflectors are in one piece with the atleast one air manifold.
 9. The ventilation device as claimed in claim 2,in which at least one partition and/or at least one deflector include(s)an electrically conductive material.
 10. The ventilation device asclaimed in, in which each duct has, over at least one portion, ageometrical section comprising: a leading edge; a trailing edge oppositethe leading edge; first and second profiles, each extending between theleading edge and the trailing edge, said at least one opening of theduct being on the first profile, said at least one opening beingconfigured so that the ejected flow of air flows along at least aportion of the first profile.
 11. The ventilation device as claimed inclaim 1, in which each duct has, over at least one portion, ageometrical section comprising: a leading edge; a trailing edge oppositethe leading edge; first and second profiles each extending between theleading edge and the trailing edge, at least one opening of the ductbeing configured on the first profile so that the ejected flow of airflows along at least a portion of the first profile and at least oneopening of the duct being configured on the second profile so that theejected flow of air flows along at least a portion of the secondprofile.
 12. A motor vehicle heat-exchange module comprising: a heatexchanger, the heat exchanger including a plurality of tubes, termedheat-exchange tubes, in which a fluid is intended to circulate; and aventilation device adapted to generate a flow of air toward theheat-exchange tubes, the ventilation device comprising: a plurality ofducts, at least one air manifold including at least one air flow inletand ports, each duct opening at one of the ends thereof into a portseparate from the air manifold, each duct having at least one openingfor the passage of a flow of air through said duct, the opening beingseparate from the ends of the corresponding duct, the opening beingsituated outside the at least one air manifold, wherein the at least oneair manifold is provided with air guides configured to guide the flow ofair passing through the air manifold.